List of practice Questions

The direction of ray of light incident on a concave mirror is shown by $PQ$ while directions in which the ray would travel after reflection is shown by four rays marked $1, 2, 3$ and $4$. Which of the four rays correctly shows the direction of reflected ray?
The direction of the induced e.m.f. is determined by
The direction cosines l, m, n, of one of the two lines connected by the relations $l -5m+ 3n = 0, 7l^2 + 5m^2 -3n^2 = 0$ are
The direction cosines of a line passing through two points $P(x_1, y_1, z_1)$ and $Q(x_2, y_2, z_2)$ are
The direction of magnetic lines of force of a bar magnet is
The dimensions of the emf of a source of current are that of
The dimensions of ( velocity )$^2$ /radius are the same as that of
The dimerisation of $NO_2$ as the temperature is lowered is accompanied by
The dipole moment of $LiH$ is $1.964 \times 10^{-29}$ cm and the interatomic distance between $Li$ and $H$ in this molecule is $1.596\, ?$. The percentage of ionic character in $LiH$ is
The dimensional formula for pressure gradient is
The dimensional formula for strain energy density is
The dimensions of (force constant + mass)$^{1/2}$ are the same as that of
The dimensional formula for amplitude of SHM is:
The dimensional formula for Magnetic induction is
The dimensional formula for magnetic moment is
The dimensional formula for Magnetic Moment of a magent is
The differential equation of all parabolas whose axis of symmetry is along axis of $x$-axis is of order
The differential equation of $y = Ae^{2x} + Be^{-2x} $ is :
The dimensional formula for acceleration, velocity and length are $a?^{-2}, \,a?^{-1}$ and $\alpha\gamma$. What is the dimensional formula for the coefficient of friction ?
The difference in angular momentum associated with the electron in the two successive orbits of hydrogen atom is
The differences between $mRNA$ and $tRNA$ are that (i) $mRNA$ has more elaborated $3$-dimensional structure due to extensive base-pairing (ii) $tRNA$ has more elaborated $3$-dimensional structure due to extensive base-pairing (iii) $tRNA$ is usually smaller than $mRNA$ (iv) $mRNA$ bears anticodon but $tRNA$ has codons,
The different steps in a nodule formation are given below. I. A mature nodule establishes a direct vascular connection with the host for exchange of nutrients. II. Root hair curls and the bacteria invade the root hair. III. Rhizobium bacteria contact a susceptile root hair, divide near it IV. The infection thread is produced carrying the bacteria and grows into the cortex of the root. V. The bacteria get modifi ed into rod-shaped bacteroids and cause inner cortical layer and pericycle to divide to form nodule. The correct sequence is
The differential equation of all non-horizontal lines in a plane is
The dielectric strength of a medium is $2\,kVmm^{-1}$ . What is the maximum potential difference that can be set up across a $50\,pm$ specimen without puncturing it.
The dielectric strength of air is $2.0\times10^6 N/C$. The largest charge that a metallic sphere of $3 \,mm$ radius can hold is